Windowed door for self-cleaning oven



June 17, 1969 A. w. voNDERHAA WINDOWED DOOR FOR SELF-CLEANING OVEN FiledFeb. 21, 1968 INVENTOR ARTHUR w. VO/VOERHAAR aZM/MMQM Fm fT'TORNEYSUnited States Patent C US. Cl. 126-200 4 Claims ABSTRACT OF THEDISCLOSURE A self-cleaning oven door having a window and a removable padapplied to the inside of the door to prevent heat loss and to shield thewindow during high temperature cleaning of the oven. The pad is hollow,contains insulation material, and is interlocked with the oven controlsso that a heat cleaning cycle cannot be initiated unless the pad isproperly in place on the door.

Disclosure This invention relates to a windowed door assembly for ovensin which cleaning of the interior surfaces is accomplished by heatingthe oven to a temperature substantially above the normal range forcooking and the like.

As explained in U.S. Patent No. 3,311,106, the first self-cleaning ovensproduced for domestic use could not be equipped with conventionalwindowed doors in view of the very high heat energy produced in thecavity in the cleaning cycle, the oven operating at a temperature above750 and usually close to 1,000 E, and the patent presents a newconstruction for such a door which includes a protective shutter for thewindow. The window in this construction has at least two glass panes andthe shutter can be moved from a concealed position within the body ofthe door to a visible position between the panes to act as a reflectiveshield during the high temperature cleaning operation. Guides must beprovided to ensure proper movement of the shield, special snubbers anddetents are required, and an exteriorly accessible actuating handle isneeded, all adding considerably to the complication and cost of thedoor.

It is a primary object of this invention to provide an improved windowedoven door assembly which is effective in retaining heat within the ovencavity during selfcleaning operation.

It is a principal object of this invention to provide an improvedwindowed oven door assembly in which the window is more eflicientlyshielded from the high heat energy during cleaning to effect a safeoperation.

Another principal object of this invention is to provide such a doorconstruction which is substantally less complicated and costly than thedoor described in the aforesaid patent.

Other objects and advantages of the present invention will becomeapparent as the following description proceeds.

To the accomplishment of the foregoing and related ends the invention,then, comprises the features hereinafter fully described andparticularly pointed out in the claims, the following description andthe annexed drawing setting forth in detail a certain illustrativeembodiment of the invention, this being indicative, however, of but oneof the various ways in which the principle of the invention may beemployed.

In said annexed drawing:

FIG. 1 is a perspective view of a self-cleaning oven range equipped witha windowed door in accordance with the present improvements;

FIG. 2 is a sectional view of the door detached from the oven andapproximately at the plane of the line 22 in FIG. 1; and

FIG. 3 is a further fragmented section proximately by the line 3-3 inFIG. 1.

Referring now to the drawing in detail, the illustrated range structure,apart from the oven door, serves only as an illustrative embodiment ofconventional construction. It comprises a free-standing cabinet 10, anoven 11 within the same, and a cook top 12 having a plurality of surfaceheating devices 13. The oven door 14 is of the drop indicated aptype andhinged to the cabinet at its bottom edge by a hinge means, alsoconventional, including lever arms 15-. A handle 16 is shown projectingfrom the cabinet above the oven, and this handle is the actuator of acombination mechanical and thermal door latch as described in thepending Anderson application Ser. No. 561,851, filed June 30, 1966,assigned to the assignee of the present application. Such latchmechanism is actuated when a heat cleaning cycle is to be carried outand it operates an interlock switch which must be thus operated beforethe cycle can be initiated; a bimetal locking device precludes releaseof the latch when the oven temperature is above a predetermined degreeas a further safety feature.

For purposes of the present application, it is also significant to notethat such combination latch mechanism includes a hook arm which enters aslot 17 at the top inside of the door when the latter is closed toengage about a keeper within this part of the door and, also, that thelatch is of the type which cannot move to the full closed or latchedposition unless the hook arm engages and experiences some restraint bythe keeper in the closing action. Reference may of course be had to saidAnderson application for further description of the latch mechanism. Theactuating handle 16 will be above the top of the door in the closedcondition of the latter. The door comprises an outer liner 18, which isflanged rearwardly about the periphery and has a flanged rectangularopening 19. The main body of the door is completed by a forwardlyflanged inner liner 20 which also has a rectangular opening 21, but ofsomewhat smaller dimensions than the outer liner opening as illustrated.A double-paned window sub-assembly is mounted within the door at theseopenings and comprises first and second glass panes 22 and 23,respectively, separated by a spacer channel 24 and enclosed by acontinuous outer channel 25. A trim frame 26 is added at the outer orfront door opening 19, and it will be seen that the inner liner isflanged inwardly at its opening 21 and carries a continuous seal 27which bears against the inner glass pane 23. A liner shield 28 isapplied to the inner door liner 20 as shown to provide an addedthickness over the major area of the door. The outer and inner doorliners are joined conventionally by screws, as typically indicated atnumerals 60; similarly, the liner shield 28 is attached to the innerliner 20 by a plurality of screws, not shown, and it will be seen thatthis shield is drawn to provide an inturned outer edge 29 and a compoundflanged rectangular opening 30 in register with the inner liner windowopening 21.

A main oven gasket 31 extends continuously about the outer edge portionof the shield and with such edge 29 engaging the gasket intermediate itswidth and thereby being insulated from the inner door liner. Such maingasket is also engaged by channel retainers 32 secured suitably to theinner liner for clamping of the gasket as shown interiorly of the linershield 28.

It will be further seen that the inner edge of the shield at opening 30is also thermally isolated from the inner liner by the interpositionbetween the two of a high temperature resilient gasket 33. The main bodyof the door defined by the outer and inner liners is filled as indicatedwith glass wool insulation 34, and the additional interior a space 35provided by the liner shield is also filled with such insulatingmaterial. The main gasket 31 is of course exposed about the liner shieldto engage and seal the front frame of the oven when the door is closed.

The construction thus far described constitutes a basically completewindowed door in the condition in which it will be used during normalcooking operations in the oven and, of course, affording the desiredview of the interior with the door closed. When a cleaning cycle is tobe undertaken, a removable pad designated generally by reference numeral36 is applied to the inside of the door as will be described in order toprotect the window from the high heat energy produced in the cavity andto contain the energy within the oven.

The pad body is formed of a first rectangular sheet 37 with a peripheralflange, a stepped intermediate frame member 38 and a second rectangularsheet 39 also flanged, but of smaller size than the first. Such piecesare assembled and suitably held together in the manner illustrated toform a hollow body the peripheral wall of which has first and secondsteps 40 and 41, respectively, with a high temperature sealing gasket 42clamped between the pieces 38 and 39 in exposed overlying relation tothe second step 41.

The dimensioning is such that the pad 36, which may be filled withsuitable insulation such as glass wool, nests within the window openingof the liner shield 28 and projects partially as well into the opening21 of the inner door liner. The first or outer step 40 of the pad whenapplied to the inside of the door thus overlies the shield 28, while thegasketed second step 41 bears against the inner shield flange 43 aboutsuch opening 21.

This removable pad will, as noted, be used only when the hightemperature operation is undertaken for cleaning of the oven and it willnormally be stored, for example, conveniently in the utility drawer 44below the oven. The pad when applied must be held in place and, in theillustrated embodiment, the retention is provided by a strap 45 securedto and extending outwardly at a slight angle as indicated from the framepiece 38, approximately at the top center of the same, and by two turnsrespectively in the lower corners of the pad. These turns each includean exposed head 46 to be turned by hand, a shaft 47 which extendsthrough the pad at the first outer step section 40 of the same, and alug 48 at the opposite projecting shaft end. The liner shield 28 has aslot 49 at the top center for insertion of the pad strap 45 and twolower corner slots 50 respectively to receive the lug ends of the turnshafts. It will be apparent that the pad is accordingly fixed in placeby first inserting the top portion and the strap, then bringing the bodyinto the flush position causing the turn lugs to enter the shield slotsprovided for the same, and then operating the turns by hand to engagethe lugs behind the shield.

The door assembly also desirably includes an interlock feature topreclude initiation of the high temperature cleaning operation unlessthe pad is applied to the door, and such interlock in the illustratedrange very simply utilizes the earlier mentioned latch mechanism byadjusting the door keeper for the same. With particular reference toFIG. 3, an interlock angle 51 is used within the door in lieu of theusual keeper, and this angle is arranged for engagement and movement bythe top retaining strap 45 of the removable pad 36. The angle 51 isguided by a track 52 attached to the inner surface of the inner doorliner 20, with one end 53 flanged and extending through a slot 54 insuch liner to the space between the liner and the shield 28 where strap45 enters the same, and the other strap end 55 being movable across thedoor latch slot 17 which receives the hook arm of the mechamsm.

It will be apparent from FIG. 3 that when the door is upright or closedand the pad is detached, the interlock angle 51 will slide downsufficiently to withdraw its upper end from the latch slot 17. However,when the pad is properly applied, the strap 45 engages the angle 51 andmoves it relatively outwardly so that its upper end portion bridges theslot 17 and is thereby in position to serve as the keeper for the latchmechanism. Since, as explained earlier, the latch cannot be fully closedwithout engagement of a keeper, and the interlock electrical switch inthe control circuit of the range will not be actuated to permitinitiation of the heat cleaning cycle unless the latch is fully closed,it will be clear that placement of the pad is a condition uponcommencement of such operation.

It is to be understood that the described interlock is preferred in theillustrated range primarily by virtue of the availability of thedescribed latch mechanism for the same, and that the range controls canbe conditioned in other ways to make the cleaning cycle similarlydependent upon the proper application of the pad to the inside of thedoor.

The structure disclosed is obviously uncomplicated and economical, andyet it provides very efiicient operation of the oven and protection forthe window. In this last connection, it is significant to note that thepad is of appreciable thickness and, filled with glass wool, representsa substantial thermal insulating mass, and also that the pad is appliedso that no glass surface is exposed to the energy in the cavity in thehigh temperature operation. The pad is thus more than a simplereflective shield and fully conceals and protects the window inparticular contrast, in both respects, to the described otherarrangement of a reflective shutter used between the glass panes.

Further, and very importantly, the action of the pad as a heat barrierprovides the advantage of containing the high heat energy within theoven. Heat dissipation through a window may be so great as to preventthe door and perhaps even the oven itself from reaching a cleaningtemperature and the structure of the door assembly of this invention issuch as to eliminate these problems. While the inner surface or sheet 37of the pad will attain a selfcleaning temperature, the isolationprovided by the material and configuration of the pad in such sealedengagement with the door, will prevent undesirable heat transfer throughthe window aperture.

It will also be evident that the new door and pad combination can beutilized with a three pane window, if desired, with a third pane addedat the inside generally in the manner disclosed also in Patent No.3,311,106. With such modification, the thickness of the removable padwould be reduced appropriately by eliminating the inner sheet 39 andmaking the frame 38 the inner pad liner or closure. This would of courseobviously accommodate the third pane mounted as in the patent, and insuch case the added pad gasket 42 might also be eliminated asunnecessary.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the following claims or the equivalent of suchbe employed.

I, therefore, particularly point out and distinctly claim as myinvention:

1. A windowed door for a self-cleaning oven, comprising outer and innerdoor panels together forming the body of the door and having laterallyspaced window openings in register, a window assembly mounted in saidbody at and closing said openings, said window assembly including atleast two spaced-apart glass panes, a pad applied to the inside of thedoor and fully covering the window assembly for shielding of the samefrom the oven cavity during high temperature cleaning operation thereof,the pad being removable from the door for viewing through the windowassembly during other oven operation, latch means in the door havingoperative and inoperative conditions of adjustment, and means responsiveto application of the pad to the door to adjust the latch means from itsinoperative to its operative condition for latching of the door.

5 6 2. The combination set forth in claim 1, wherein the overlies theinner panel and another part extends into pad is hollow and filled withthermal insulation material. the recess adjacent such inner pane.

3. The combination set forth in claim 1, wherein the latch meansincludes a keeper portion for engagement References Cited with a latchmember, the door having an opening to re- 5 UNITED STATES PATENTS ceivesuch member and ad uStment of the latch means moving said keeper portionrelative to such opening. 2,963,019 12/ 1960 Domsky 126-2()0 4. Thecombination set forth in claim 1, wherein the 2,859,744 11/1958 Hadley126-200 XR glass pane at the inside of the door is recessed relative3,311,106 3/1967 Baughman et a1 126-200 to the inner panel, the pad hasappreciable thickness, and 10 the periphery of the pad is stepped sothat an outer part KENNETH W. SPRAGUE, Primary Examiner.

